effect of l-arginine on microcirculation, myogenesis and angiogenesis associated with aging, sarcopenia and diabetes

Conditions: Aging; Sarcopenia; Type 2 Diabetes; Microcirculation

Summary: this study aims was evaluated the effect of l-arginine on microcirculation, vasoreactivity / endothelial function and vascular smooth muscle of young and old women with sarcopenia or type 2 diabetes mellitus measured by nailfold videocapillaroscopy and venous occlusion plethysmography before and after 14 days of consumption 5g oral l-arginine supplementation.

aging causes responsible endothelial changes, in part by a decrease in the blood flow of the skeletal muscles of the elderly. reduction of muscle mass / function (sarcopenia) and diabetes mellitus are frequent pathologies in the elderly. l-arginine is a semi-essential amino acid precursor to nitric oxide synthesis (no), an important vasodilator and protector cardiovascular. seventy-five women were allocated into three groups: twenty-five healthy young (hy) recruited among university students, and fifty women elderly, this was stratified in twenty-five healthy elderly (he) control and twenty-five with hyperglycemia (hg) elderly from the ambulatories of the geriatric and diabetology at the state university of rio de janeiro (uerj) and private supplementary health program. to control group was considered absence cardiovascular risk factor except advanced age. participants were subjected to screening phase before being eligible for the study by telephone, which comprised of individual clinical history. all subjects signed the written informed consent form enclosed in the protocol approved by ethics committee from the state university of rio de janeiro according to helsinki declaration. the subjects elected for research made 4 visits to the biovasc laboratory for data collection. first day: the protocol was explained and agreement from the voluntary obtained, followed and anamnesis and physical exam that included measure at-rest blood pressure, weight and height. moreover, women examined after 6 hours fasting the microcirculation function using nailfold vidiocapilaroscopy (nvc), followed of the measure of forearm blood flow (fbf) and vascular reactivity by venous occlusion plethysmography (vop). second day: venous blood sample collection after 12 hours fasting. in sequence, they realized whole-body dual-energy x-ray absorptiometry (dxa) to calculate the body composition main measure lean and fat mass. after, was delivered a box with 14 sachets content 5g l-arginine supplementation, and it was recommended to ingest with water 30 minutes before breakfast during 14 days. third day: return after the supplementation to realize measurement weight, and exams nvc and vop. fourth day: blood sample were taken after 12 hours fasting under effect of the l-arginine.

Eligibility criteria:
inclusion criteria: * young women aged between 20 - 30 years, imc \< 24.9 kg/m2 * older women over 65 years healthy, bmi \<35 kg/m2. * elderly women with or without a preexisting diagnosis of diabetes mellitus with fasting plasma glucose (fpg) \> 100 mg/dl were classified into type 2 diabetes mellitus. exclusion criteria: * involved type 1 diabetes mellitus * insulin use, cognitive impairment * frailty * disorders cardiometabolic * liver and/or kidney dysfunction * autoimmune diseases * smoking * rigorous exercise * uncontrolled hypertension with pressure level \> 140/90 mmhg, with up to two antihypertensive drugs of different classes.

Keywords: l-arginine asymmetric dimethylarginine arginase sarcopenia myostatin follistatin type 2 diabetes mellitus vascular smooth muscle endothelial function